One witness. One assassin's bullet. One explosive secret that could bring down the most powerful men in Washington.

When Evangeline Lockwood witnesses the assassination of a high-profile politician, she becomes the most hunted woman in America. With professional killers closing in and nowhere to turn, her father—former CIA Deputy Director—makes a desperate call to the one organization he trusts: Dynamis Security.

Elite operative Calvin Cruz didn't sign up for babysitting duty. With a reputation for working alone and a past shrouded in classified operations, the last assignment he wants is protection detail for a diplomat's daughter. But Atticus Cameron, head of Dynamis, has given him no choice.

As danger escalates and safe houses are compromised, Calvin discovers there's more to Evangeline than the privileged daughter he expected—she's keeping secrets that make her both a liability and an enigma. In a game where trust is currency and betrayal is a professional hazard, Calvin's already paid the price once with a knife in his back.

He won't make that mistake again. Not even for the woman who's beginning to breach the fortress around his heart.